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1.
BMC Oral Health ; 20(1): 90, 2020 03 29.
Artigo em Inglês | MEDLINE | ID: mdl-32223762

RESUMO

BACKGROUND: Decades of epidemiological studies have documented high rates of early childhood caries (ECC) among American Indian and Alaska Native (AIAN) children. The aim of this pilot study was to investigate if a motivational interviewing (MI) intervention improved oral self-care behaviors of AIAN caregivers of infants, and determine if the MI intervention promoted positive changes in caregivers' ECC risk-related behaviors. METHODS: Caregivers of infants presenting for well- child visits in a medical clinic were randomized to treatment and control groups. At the first visit, a caries risk test (CRT) for cariogenic bacteria was completed for both groups. The Parental Care of Child's Teeth (PCCT) was administered at the second visit and used to assess ECC risk-related behaviors. Over the course of four well-child visits, caregivers in the treatment group participated in a MI discussion focusing on behavior changes and desired outcomes for their personal oral health and their child's. The duration of the intervention was 1 year. The control group was given oral health information traditionally provided at well-child visits. At the fourth well-child visit, the CRT and PCCT questionnaire were administered again. RESULTS: The mean bacterial load for mutans streptococcus (MS) was similar at both visits. A slight reduction in the mean bacterial levels of lactobacilli was observed in both the test and control groups after the last visit, although not at a level of statistical significance. The treatment group showed minimal improvement in child feeding practices and nighttime bottle habits. CONCLUSIONS: Motivational Interviewing had little effect on oral self-care behaviors as measured by bacterial load, nor did MI reduce parental risk related behavior for early childhood caries. TRIAL REGISTRATION: Clinicaltrials.gov# NCT04286256. Retrospectively registered, February 26, 2020.


Assuntos
Cárie Dentária/prevenção & controle , Entrevista Motivacional , Saúde Bucal , Pais/psicologia , Criança , Pré-Escolar , Comportamentos Relacionados com a Saúde , Humanos , Lactente , Projetos Piloto
2.
Appl Environ Microbiol ; 84(7)2018 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-29352083

RESUMO

Bacteria that accumulate polyphosphates have previously been shown to dynamically influence the solubility of phosphatic minerals in marine settings and wastewater. Here, we show that dental plaque, saliva, and carious lesions all contain abundant polyphosphate-accumulating bacteria. Saturation state modeling results, informed by phosphate uptake experiments using the model organism Lactobacillus rhamnosus, which is known to inhabit advanced carious lesions, suggest that polyphosphate accumulation can lead to undersaturated conditions with respect to hydroxyapatite under some oral cavity conditions. The cell densities of polyphosphate-accumulating bacteria we observed in some regions of oral biofilms are comparable to those that produce undersaturated conditions (i.e., those that thermodynamically favor mineral dissolution) in our phosphate uptake experiments with L. rhamnosus These results suggest that the localized generation of undersaturated conditions by polyphosphate-accumulating bacteria constitutes a new potential mechanism of tooth dissolution that may augment the effects of metabolic acid production.IMPORTANCE Dental caries is a serious public health issue that can have negative impacts on overall quality of life and oral health. The role of oral bacteria in the dissolution of dental enamel and dentin that can result in carious lesions has long been solely ascribed to metabolic acid production. Here, we show that certain oral bacteria may act as a dynamic shunt for phosphate in dental biofilms via the accumulation of a polymer known as polyphosphate-potentially mediating phosphate-dependent conditions such as caries (dental decay).


Assuntos
Bactérias/metabolismo , Cárie Dentária/microbiologia , Placa Dentária/microbiologia , Polifosfatos/metabolismo , Saliva/microbiologia , Adolescente , Criança , Pré-Escolar , Feminino , Humanos , Masculino , Boca/microbiologia
3.
Surg Radiol Anat ; 40(6): 653-665, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29353372

RESUMO

INTRODUCTION: This study was designed to quantify the important anatomical landmarks and the path of the inferior alveolar nerve (IAN) within the human mandibular body and ramus, in particular with reference to the bilateral sagittal split osteotomy (BSSO). MATERIALS AND METHODS: Four hundred and eleven CT scans were studied, 299 of these were involved in determining the position of lingula; and 230 were involved in determining the course of IAN in the mandibular molar region, namely from the mesial of the mandibular first molar to the distal of the mandibular second molar; 118 were involved with both measurements. RESULTS: On average, the lingula was located 17.0 ± 2.2 mm from the external oblique ridge; 11.6 ± 2.0 mm from the internal oblique ridge; 17.2 ± 2.7 mm from the sigmoid notch; and 15.6 ± 1.9 mm from the posterior border of the mandible. The course of the IAN in the mandibular molar region was found to descend vertically from the distal of the mandibular second molar (7) to reach its lowest point between the first and second molars (6 and 7), and then ascend towards the mesial of the first molar (6). Horizontally, the IAN was found to traverse medially between the distal of the 7 and the middle of the 7, and then changes its path laterally towards the mesial of the 6. CONCLUSION: Precise knowledge of the individual's position of the IAN will help surgical planning.


Assuntos
Pontos de Referência Anatômicos/anatomia & histologia , Variação Anatômica , Mandíbula/anatomia & histologia , Nervo Mandibular/anatomia & histologia , Osteotomia Sagital do Ramo Mandibular/efeitos adversos , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Pontos de Referência Anatômicos/diagnóstico por imagem , Pontos de Referência Anatômicos/cirurgia , Criança , Feminino , Humanos , Imageamento Tridimensional , Masculino , Mandíbula/diagnóstico por imagem , Mandíbula/cirurgia , Pessoa de Meia-Idade , Dente Molar/anatomia & histologia , Dente Molar/diagnóstico por imagem , Osteotomia Sagital do Ramo Mandibular/métodos , Complicações Pós-Operatórias/etiologia , Complicações Pós-Operatórias/prevenção & controle , Tomografia Computadorizada por Raios X , Traumatismos do Nervo Trigêmeo/etiologia , Traumatismos do Nervo Trigêmeo/prevenção & controle , Adulto Jovem
4.
N Engl J Med ; 369(8): 722-31, 2013 Aug 22.
Artigo em Inglês | MEDLINE | ID: mdl-23964934

RESUMO

BACKGROUND: Pazopanib and sunitinib provided a progression-free survival benefit, as compared with placebo or interferon, in previous phase 3 studies involving patients with metastatic renal-cell carcinoma. This phase 3, randomized trial compared the efficacy and safety of pazopanib and sunitinib as first-line therapy. METHODS: We randomly assigned 1110 patients with clear-cell, metastatic renal-cell carcinoma, in a 1:1 ratio, to receive a continuous dose of pazopanib (800 mg once daily; 557 patients) or sunitinib in 6-week cycles (50 mg once daily for 4 weeks, followed by 2 weeks without treatment; 553 patients). The primary end point was progression-free survival as assessed by independent review, and the study was powered to show the noninferiority of pazopanib versus sunitinib. Secondary end points included overall survival, safety, and quality of life. RESULTS: Pazopanib was noninferior to sunitinib with respect to progression-free survival (hazard ratio for progression of disease or death from any cause, 1.05; 95% confidence interval [CI], 0.90 to 1.22), meeting the predefined noninferiority margin (upper bound of the 95% confidence interval, <1.25). Overall survival was similar (hazard ratio for death with pazopanib, 0.91; 95% CI, 0.76 to 1.08). Patients treated with sunitinib, as compared with those treated with pazopanib, had a higher incidence of fatigue (63% vs. 55%), the hand-foot syndrome (50% vs. 29%), and thrombocytopenia (78% vs. 41%); patients treated with pazopanib had a higher incidence of increased levels of alanine aminotransferase (60%, vs. 43% with sunitinib). The mean change from baseline in 11 of 14 health-related quality-of-life domains, particularly those related to fatigue or soreness in the mouth, throat, hands, or feet, during the first 6 months of treatment favored pazopanib (P<0.05 for all 11 comparisons). CONCLUSIONS: Pazopanib and sunitinib have similar efficacy, but the safety and quality-of-life profiles favor pazopanib. (Funded by GlaxoSmithKline Pharmaceuticals; COMPARZ ClinicalTrials.gov number, NCT00720941.).


Assuntos
Inibidores da Angiogênese/uso terapêutico , Carcinoma de Células Renais/tratamento farmacológico , Indóis/uso terapêutico , Neoplasias Renais/tratamento farmacológico , Pirimidinas/uso terapêutico , Pirróis/uso terapêutico , Sulfonamidas/uso terapêutico , Adulto , Inibidores da Angiogênese/efeitos adversos , Carcinoma de Células Renais/secundário , Intervalo Livre de Doença , Método Duplo-Cego , Feminino , Humanos , Indazóis , Indóis/efeitos adversos , Estimativa de Kaplan-Meier , Neoplasias Renais/patologia , Masculino , Pirimidinas/efeitos adversos , Pirróis/efeitos adversos , Qualidade de Vida , Sulfonamidas/efeitos adversos , Sunitinibe
5.
J Transl Med ; 14: 27, 2016 Jan 27.
Artigo em Inglês | MEDLINE | ID: mdl-26818763

RESUMO

BACKGROUND: Craniomaxillofacial defects secondary to trauma, tumor resection, or congenital malformations are frequent unmet challenges, due to suboptimal alloplastic options and limited autologous tissues such as bone. Significant advances have been made in the application of adipose-derived stem/stromal cells (ASCs) in the pre-clinical and clinical settings as a cell source for tissue engineering approaches. To fully realize the translational potential of ASCs, the identification of optimal donors for ASCs will ensure the successful implementation of these cells for tissue engineering approaches. In the current study, the impact of obesity on the osteogenic differentiation of ASCs was investigated. METHODS: ASCs isolated from lean donors (body mass index <25; lnASCs) and obese donors (body mass index >30; obASCs) were induced with osteogenic differentiation medium as monolayers in an estrogen-depleted culture system and on three-dimensional scaffolds. Critical size calvarial defects were generated in male nude mice and treated with scaffolds implanted with lnASCs or obASCs. RESULTS: lnASCs demonstrated enhanced osteogenic differentiation in monolayer culture system, on three-dimensional scaffolds, and for the treatment of calvarial defects, whereas obASCs were unable to induce similar levels of osteogenic differentiation in vitro and in vivo. Gene expression analysis of lnASCs and obASCs during osteogenic differentiation demonstrated higher levels of osteogenic genes in lnASCs compared to obASCs. CONCLUSION: Collectively, these results indicate that obesity reduces the osteogenic differentiation capacity of ASCs such that they may have a limited suitability as a cell source for tissue engineering.


Assuntos
Tecido Adiposo/citologia , Diferenciação Celular , Obesidade/patologia , Osteogênese , Células-Tronco/citologia , Adulto , Animais , Diferenciação Celular/efeitos dos fármacos , Diferenciação Celular/genética , Colágeno/metabolismo , Feminino , Perfilação da Expressão Gênica , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Peptídeos e Proteínas de Sinalização Intercelular/deficiência , Ácido Láctico/farmacologia , Camundongos Nus , Obesidade/genética , Osteoclastos/efeitos dos fármacos , Osteoclastos/patologia , Osteogênese/efeitos dos fármacos , Osteogênese/genética , Ácido Poliglicólico/farmacologia , Copolímero de Ácido Poliláctico e Ácido Poliglicólico , Crânio/patologia , Células-Tronco/efeitos dos fármacos , Células-Tronco/metabolismo , Magreza/genética , Magreza/patologia , Alicerces Teciduais/química
6.
Biotechnol Bioeng ; 113(1): 198-205, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26156808

RESUMO

The objective of this study was to develop a method to reliably and reproducibly assess the physical properties of in vitro multi-species plaque derived biofilms. A custom flow cell (FC) was designed to model oral cavity shear stresses on biofilms grown on hydroxyapatite (HA) discs. A finite-element program (ANSYS 13) modeled flow velocities and wall shear stresses on the interior 3D dimensions. For the experiment, 1% chlorhexidine (CHX), 5 M urea, and a 1× phosphate-buffered saline (PBS) were flown through the FC simulating oral rinsing. Near infrared cross-polarization optical coherence tomography (CP-OCT) non-destructively imaged the fluid immersed biofilms in real time (20 frames/s). During low flow, the swell of the biofilm caused from 5 M urea was quite pronounced increase in vertical dimension. Biofilms exposed to 1% CHX showed a slight collapse in the vertical dimension of the biofilm during low flow. During high flow/high sheer stress, the 5 M urea solution effectively removed the biofilm, while both 1% CHX and 1× PBS did not remove biofilms even under high velocity/shear stress conditions.


Assuntos
Biofilmes/efeitos dos fármacos , Placa Dentária/microbiologia , Processamento de Imagem Assistida por Computador/métodos , Tomografia de Coerência Óptica/métodos , Anti-Infecciosos/farmacologia , Técnicas Microbiológicas , Modelos Biológicos , Fatores de Tempo
7.
Clin Orthop Relat Res ; 472(7): 2208-14, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24658903

RESUMO

BACKGROUND: Periprosthetic joint infection is a leading cause of failure after two-stage reimplantation. One cause of relapse may be persistent subclinical infection. Difficulty exists in detecting biofilm-forming infections. Sonication disrupts biofilm and has led to higher rates of positive intraoperative cultures. QUESTIONS/PURPOSES: Our aims in this study were to determine (1) if sonication results were predictive of failure, including reinfection, at 2-year followup; and (2) whether sonication of antibiotic spacers at the time of reimplantation improves sensitivity of intraoperative cultures. METHODS: We prospectively followed 36 consecutive patients undergoing two-stage reimplantation for periprosthetic hip or knee infection. Minimum followup was 19 months (mean, 29.9 months; range, 19­38 months). Results of intraoperative cultures and sonicated antibiotic spacers were analyzed. RESULTS: Positive sonication results were predictive of failure as defined by reinfection at 2-year followup. Among the 18 patients who had positive sonication results, reinfection developed in nine patients (50%) compared with two of 18 patients (11%) with negative sonication results (odds ratio, 8.0; 95% CI, 1.2­69.0). Sonication of antibiotic spacers improved the sensitivity of intraoperative cultures from 45% to 82%. [corrected]. CONCLUSIONS: Sonication of antibiotic spacers appears to be useful in predicting failure attributable to recurrent infection after two-stage reimplantation. For patients with positive sonication cultures during reimplantation, more aggressive antimicrobial treatment may be indicated after reimplantation. LEVEL OF EVIDENCE: Level III, diagnostic study. See the Instructions for Authors for a complete description of levels of evidence.


Assuntos
Antibacterianos/administração & dosagem , Artroplastia de Quadril/efeitos adversos , Artroplastia de Quadril/instrumentação , Artroplastia do Joelho/efeitos adversos , Artroplastia do Joelho/instrumentação , Cimentos Ósseos/uso terapêutico , Prótese de Quadril/efeitos adversos , Prótese do Joelho/efeitos adversos , Infecções Relacionadas à Prótese/cirurgia , Sonicação , Adulto , Idoso , Idoso de 80 Anos ou mais , Técnicas Bacteriológicas , Biofilmes/efeitos dos fármacos , Biofilmes/crescimento & desenvolvimento , Feminino , Seguimentos , Prótese de Quadril/microbiologia , Humanos , Prótese do Joelho/microbiologia , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Desenho de Prótese , Infecções Relacionadas à Prótese/diagnóstico , Infecções Relacionadas à Prótese/microbiologia , Recidiva , Reoperação , Estudos Retrospectivos , Fatores de Risco , Fatores de Tempo , Falha de Tratamento , Adulto Jovem
8.
BMC Oral Health ; 13: 16, 2013 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-23537067

RESUMO

BACKGROUND: Optical caries detection has the potential to be incorporated in telehealth medicine for preventive dental screening. The objective of this study was to evaluate and compare visible and near infrared detection methods for identifying early non-cavitated ex vivo occlusal demineralization. METHODS: Six blinded examiners were used to compare the accuracy of the following three examinations in detecting occlusal demineralization: Midwest Caries ID (MID), visual photographic examination (CAM) and Cross Polarization Optical Coherence Tomography (CP-OCT). For each diagnostic method, two examiners assessed the extracted tooth samples 1-2 weeks apart. Teeth were then sectioned and lesion depth was confirmed (n = 42) by a blinded histological examination using a glycol based caries indicator dye. The sensitivity (Sen), specificity (Sp), Intraclass Correlation Coefficient (ICC), and Area under the Receiver Operator Curve (AUC) were calculated. RESULTS: For detecting any demineralization versus sound pit and fissure enamel, the mean Sen/Sp found was 46.9/85.0 for MID, 80.5/52.5 for CAM, and 83.4/45.0 for CP-OCT. For detecting non-cavitated demineralization that progressed into the dentin, the mean Sen/Sp found was 17.3/88.0 for MID, 48.0/57.8 for CAM, and 44.2/72.7 for CP-OCT. AUC values were statistically significant (P < 0.05) in three out of four examiner assessments when MID and CP-OCT were used to detect any demineralization. AUC values were significant for a single CAM examination. When assessing deeper non-cavitated lesions, none of the assessment methods were able to yield AUC values that were significantly different than a random 'coin flip' test. When examining reliability, MID demonstrated the highest ICC score (0.83) and CP-OCT had the lowest (0.49). CONCLUSION: Although MID and CP-OCT were useful in detecting the presence of demineralization, examiners were not able to utilize these devices to adequately assess the depth of the demineralization. This study found that MID and CP-OCT did not have markedly superior diagnostic values from simple CAM assessment for use in teledentistry.


Assuntos
Cárie Dentária/diagnóstico , Informática Odontológica , Processamento de Imagem Assistida por Computador , Telemedicina , Corantes , Esmalte Dentário/patologia , Dentina/patologia , Humanos , Luz , Microscopia de Polarização , Variações Dependentes do Observador , Fotografia Dentária , Propilenoglicóis , Reprodutibilidade dos Testes , Rodaminas , Semicondutores , Sensibilidade e Especificidade , Método Simples-Cego , Tomografia de Coerência Óptica
9.
J Dent Child (Chic) ; 90(3): 139-146, 2023 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-38123932

RESUMO

Purpose: To examine the influence of substituting intranasal (IN) midazolam (MID) for oral (PO) MID, within the three-drug combination of meperidine (MEP), hydroxyzine (H) and MID, on sedation treatment outcomes. Methods: A retrospective, cross-sectional analysis examined patient variables and sedation outcomes in 508 pediatric dental patients sedated by single- and multi-drug sedation regimens (MEP-H; MEP-H-(PO)-MID; MEP-H-(IN)-MID; single-agent MID). The outcome assessment examined sedation visit effectiveness, sedation treatment completion, treatment time and medication administration to discharge time. Multivariable logistic regression analyses assessed predictive variables associated with sedation visit effectiveness. Results: Both three-drug combinations (MEP-H-(PO)-MID; MEP-H-(IN)-MID) were used for behavior guidance in children of a similar age (median age=7.1 and 6.5 years, respectively, for the two drug combinations) and weight (median weight = 23.7 and 23.5 kg, respectively, for the two drug combinations). These three-drug combinations had a higher likelihood of sedation effectiveness over the reference sedation regimen of single-agent midazolam (MEP-H-(PO)-MID adjusted odds ratio [OR] = 2.65; 95 percent confidence interval [95% CI]=1.09 to 6.45; P=0.032; and MEP-H-(IN)-MID OR=2.08; 95% CI=1.03 to 4.18; P=0.039). MEP-H-(IN)MID was associated with a shorter medication administration to discharge time for patients by 23 minutes (interquartile range [IQR]=9.5 to 34 minutes) compared to MEP-H-(PO) MID (P<0.05) while providing a comparable number of teeth treated (median=five). All sedation drug regimens, including MEP-H-(IN)MID, had high levels of oxygen saturation during all sedation appointments. Conclusion: Substituting IN for PO MID in MEP-H-MID was associated with a shorter total time to discharge while demonstrating comparable efficacy during sedation.


Assuntos
Anestesia Dentária , Midazolam , Humanos , Criança , Midazolam/efeitos adversos , Hidroxizina/efeitos adversos , Meperidina , Hipnóticos e Sedativos , Sedação Consciente , Estudos Retrospectivos , Estudos Transversais , Combinação de Medicamentos
10.
Evid Based Dent ; 13(3): 76-7, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-23059919

RESUMO

DATA SOURCES: Medline, Embase, Cochrane Central Register of Controlled Trials, Dissertation Abstracts, SIGLE, the WorldWideWeb (Google) and the Community of Science Database were searched for relevant trials and references. Reference lists from relevant articles were scanned and the authors contacted to identify trials and obtain additional information. There were no language restrictions. Trials pre-1966 were not searched. STUDY SELECTION: Studies were included if they were randomised controlled trials of conscious sedation comparing two or more drugs/techniques/placebo undertaken by the dentist or one of the dental team in children up to 16 years of age. DATA EXTRACTION AND SYNTHESIS: Reference lists from relevant articles were scanned and the authors contacted to identify trials and obtain additional information. There were no language restrictions. Trials pre-1966 were not searched. RESULTS: Thirty-six studies (2810 participants) were included. The majority of the trials (30) were of high risk of bias, the other six trials were at unclear risk of bias. Twenty-eight different sedatives were used with or without inhalational nitrous oxide, and the dosages, mode and timing of administration varied greatly. The trials were grouped into placebo-controlled, dosage and head-to-head comparisons. Meta-analysis was possible for studies investigating oral midazolam vs placebo only. There is weak evidence from five trials at high risk of bias, that the use of oral midazolam in doses between 0.25 mg/kg to 0.75 mg/kg is associated with more co-operative behaviour compared to placebo; standardised mean difference (SMD) favoured midazolam (SMD 2.98, 95% CI 1.58 to 4.37, P < 0.001, I² = 91%). There was also very weak evidence from two trials which could not be pooled that inhalational nitrous oxide is more effective than placebo. CONCLUSIONS: There is some weak evidence that oral midazolam is an effective sedative agent for children undergoing dental treatment. There is very weak evidence that nitrous oxide inhalation may also be effective. There is a need for further well designed and well reported clinical trials to evaluate other potential sedation agents. Further recommendations for future research are described and it is suggested that future trials evaluate experimental regimens in comparison with oral midazolam or inhaled nitrous oxide.


Assuntos
Ansiolíticos/uso terapêutico , Ansiedade ao Tratamento Odontológico/tratamento farmacológico , Assistência Odontológica para Crianças/psicologia , Hipnóticos e Sedativos/uso terapêutico , Humanos
11.
Pediatr Dent ; 44(5): 340-344, 2022 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-36309778

RESUMO

Purpose: The purpose of this retrospective cross-sectional study was to examine protective stabilization (PS) patterns before and after the availability of weighted blankets (WBs) as a behavioral guidance approach during in-office dental moderate sedation. Methods: A retrospective chart review evaluated pediatric patient sedation records after six-pound lead-free WBs were introduced into the dental clinic and compared clinical outcomes to a time before WBs were available. Multivariable logistic regression analyses assessed variables associated with the occurrence of PS use during a sedation visit. Results: PS (PS) usage decreased from 78.7 percent before to 32.8 percent after the availability of WBs during sedation visits (chi-square, P<0.001). Increase in age (adjusted odds ratio [OR] equals 0.69, 95 percent confidence interval [95% CI] equals 0.53 to 0.90, P=0.006) and WB use reduced PS management (adjusted OR equals 0.067, 95% CI equals 0.020 to 0.22, P<0.001). Body mass index, gender, treatment amount, and sedation regimen did not predict the occurrence of PS. The number of completed teeth treated was not found to be statistically different between cases managed with PS versus those managed without restraint. Children managed with PS but without WBs had statistically higher heart rate changes (20.26±23.17) during treatment than children managed without restraint (8.12±15.15). Conclusions: An increase in age and weighted blanket use was associated with a reduction in the occurrence of protective stabilization during moderate sedation dental visits at the university pediatric dental clinic. Clinical practice sedation protocols should consider weighted blanket use as an alternative to PS.


Assuntos
Sedação Consciente , Criança , Humanos , Estudos Retrospectivos , Estudos Transversais , Protocolos Clínicos
12.
Artigo em Inglês | MEDLINE | ID: mdl-37377937

RESUMO

Current resin composites have favorable handling and upon polymerization initial physical properties that allow for efficient material replacement of removed carious tooth structure. Dental resin composites have long term durability limitations due to the hydrolysis of ester bonds within the methacrylate based polymer matrix. This article outlines the importance of ester bonds positioned internal to the carbon-carbon double bond in current methacrylate monomers. Water and promiscuous salivary/bacterial esterase activity can initiate ester bond hydrolysis that can sever the polymer backbone throughout the material. Recent studies have custom synthesized, with the latest advances in modern organic chemical synthesis, a novel molecule named ethylene glycol bis (ethyl methacrylate) (EGEMA). EGEMA was designed to retain the reactive acrylate units. Upon intermolecular polymerization of vinyl groups, EGEMA ester groups are positioned outside the backbone of the polymer chain. This review highlights investigation into the degradation resistance of EGEMA using buffer, esterase, and microbial storage assays. Material samples of EGEMA had superior final physical and mechanical properties than traditional ethylene glycol dimethacrylate (EGDMA) in all degradation assays. Integrating bioinformatics-based biodegradation predictions to the experimental results of storage media analyzed by LC/GC-MS revealed that hydrolysis of EGEMA generated small amounts of ethanol while preserving the strength bearing polymer backbone. Prior studies support investigation into additional custom synthesized methacrylate polymers with "flipped external" ester groups. The long term goal is to improve clinical durability compared to current methacrylates while retaining inherent advantages of acrylic based chemistry, which may ease implementation of these novel methacrylates into clinical practice.

13.
J Biomed Mater Res B Appl Biomater ; 110(5): 991-1000, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-34855282

RESUMO

This study tests biodegradation resistance of a custom synthesized novel ethylene glycol ethyl methacrylate (EGEMA) with ester bond linkages that are external to the central polymer backbone when polymerized. Ethylene glycol dimethacrylate (EGDMA) with internal ester bond linkages and EGEMA discs were prepared in a polytetrafluoroethylene (PTFE) mold using 40 µl macromer and photo/co-initiator mixture cured for 40 s at 1000 mW/cm2 . The discs were stored in the constant presence of Streptococcus mutans (S. mutans) in Todd Hewitt Yeast + Glucose (THYE+G) media up to 9 weeks (n = 8 for each macromer type) and physical/mechanical properties were assessed. Initial measurements EGEMA versus EGDMA polymer discs showed equivalent degree of conversion (45.69% ± 2.38 vs. 46.79% ± 4.64), diametral tensile stress (DTS; 8.12± 2.92 MPa vs. 6.02 ± 1.48 MPa), and low subsurface optical defects (0.41% ± 0.254% vs. 0.11% ± 0.074%). The initial surface wettability (contact angle) was slightly higher (p ≤ .012) for EGEMA (62.02° ± 3.56) than EGDMA (53.86° ± 5.61°). EGDMA showed higher initial Vicker's hardness than EGEMA (8.03 ± 0.88 HV vs. 5.93 ± 0.69 HV; p ≤ .001). After 9 weeks of S. mutans exposure, EGEMA (ΔDTS-1.30 MPa) showed higher resistance to biodegradation effects with a superior DTS than EGDMA (ΔDTS-6.39 MPa) (p = .0039). Visible and scanning electron microscopy images of EGEMA show less surface cracking and defects than EGDMA. EGDMA had higher loss of material (18.9% vs. 8.5%, p = .0009), relative changes to fracture toughness (92.5% vs. 49.2%, p = .0022) and increased water sorption (6.1% vs. 1.9%, p = .0022) compared to EGEMA discs. The flipped external ester group linkage design is attributed to EGEMA showing higher resistance to bacterial degradation effects than an internal ester group linkage design methacrylate.


Assuntos
Metacrilatos , Polímeros , Ésteres , Teste de Materiais , Metacrilatos/química , Metacrilatos/farmacologia , Polimerização , Streptococcus mutans
14.
Dent Mater ; 38(2): 251-265, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34933759

RESUMO

OBJECTIVE: The region of failure for current methacrylates (i.e. derivatives of acrylates) are ester bond linkages that hydrolyze in the presence of salivary and bacterial esterases that break the polymer network backbone. This effect decreases the mechanical properties of methacrylate-based materials. METHODS: The ethylene glycol dimethacrylate (EGDMA) or novel ethylene glycol ethyl methacrylate (EGEMA) discs were prepared using 40 µL of the curing mixture containing photo/co-initiators for 40 s in a PTFE mold at 1000 mW/cm2. The degree of conversion was used as a quality control measure for the prepared discs, followed by physical, mechanical, and chemical characterization of discs properties before and after cholesterol esterase treatment. RESULTS: After 9 weeks of standardized cholesterol esterase (CEase) exposure, EGDMA discs showed exponential loss of material (p = 0.0296), strength (p = 0.0014) and increased water sorption (p = 0.0002) compared to EGEMA discs. We integrated a degradation prediction pathway system to LC/MS and GC/MS analyses to elucidate the degradation by-products of both EGEMA and EGDMA polymers. GC/MS analysis demonstrated that the esterase catalysis was directed to central polymer backbone breakage, producing ethylene glycol, for EGDMA, and to side chain breakage, producing ethanol, for EGEMA. The flipped external ester group linkage design is attributed to EGEMA showing higher resistance to esterase biodegradation and changes in mechanical and physical properties than EGDMA. SIGNIFICANCE: EGEMA is a potential substitute for common macromer diluents, such as EGDMA, based on its resistance to biodegradation effects. This work inspires the flipped external group design to be applied to analogs of current larger, hydrophobic strength bearing macromers used in future dental material formulations.


Assuntos
Ésteres , Polímeros , Resinas Compostas/química , Esterases , Teste de Materiais , Metacrilatos/química
15.
ACS Nano ; 16(10): 16497-16512, 2022 10 25.
Artigo em Inglês | MEDLINE | ID: mdl-36245096

RESUMO

Biomaterial-associated infections are one of the major causes of implant failure. These infections result from persistent bacteria that have adhered to the biomaterial surface before, during, or after surgery and have formed a biofilm on the implant's surface. It is estimated that 4 to 10% of implant surfaces are contaminated with bacteria; however, the infection rate can be as high as 30% in intensive care units in developed countries and as high as 45% in developing countries. To date, there is no clinical solution to prevent implant infection without relying on the use of high doses of antibiotics supplied systemically and/or removal of the infected device. In this study, melimine, a chimeric cationic peptide that has been tested in Phase I and II human clinical trials, was immobilized onto the surface of 3D-printed medical-grade polycaprolactone (mPCL) scaffolds via covalent binding and adsorption. X-ray photoelectron spectroscopy (XPS) and time-of-flight secondary ion mass spectrometry (ToF-SIMS) spectra of melimine-treated surfaces confirmed immobilization of the peptide, as well as its homogeneous distribution throughout the scaffold surface. Amino acid analysis showed that melimine covalent and noncovalent immobilization resulted in a peptide density of ∼156 and ∼533 ng/cm2, respectively. Furthermore, we demonstrated that the immobilization of melimine on mPCL scaffolds by 1-ethyl-3-[3-(dimethylamino)propyl] carbodiimide hydrochloride (EDC) coupling and noncovalent interactions resulted in a reduction of Staphylococcus aureus colonization by 78.7% and 76.0%, respectively, in comparison with the nonmodified control specimens. Particularly, the modified surfaces maintained their antibacterial properties for 3 days, which resulted in the inhibition of biofilm formation in vitro. This system offers a biomaterial strategy to effectively prevent biofilm-related infections on implant surfaces without relying on the use of prophylactic antibiotic treatment.


Assuntos
Peptídeos Catiônicos Antimicrobianos , Pseudomonas aeruginosa , Humanos , Peptídeos Catiônicos Antimicrobianos/química , Biofilmes , Antibacterianos/farmacologia , Antibacterianos/química , Materiais Revestidos Biocompatíveis/química , Bactérias , Aminoácidos , Carbodi-Imidas/farmacologia , Impressão Tridimensional
16.
J Clin Med ; 10(6)2021 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-33803990

RESUMO

Alpha-adrenergic agonists, such as the Imidazoline derivatives (ImDs) of oxymetazoline and xylometazoline, are highly effective hemostatic agents. ImDs have not been widely used in dentistry but their use in medicine, specifically in ophthalmology and otolaryngology, warrants consideration for pulpal hemostasis. This review presents dental healthcare professionals with an overview of ImDs in medicine. ImD solutions have the potential to be more effective and biocompatible than existing topical hemostatic compounds in pulpal management. Through a comprehensive analysis of the pharmacology of ImDs and the microphysiology of hemostasis regulation in oral tissues, a conceptual model of pulpal management by ImD solutions is presented.

17.
ANZ J Surg ; 91(11): 2459-2465, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34514684

RESUMO

BACKGROUND: Postoperative pancreatic fistula (POPF) remains a significant cause of morbidity in patients undergoing distal pancreatectomy (DP). The use of polyethylene glycol (PEG) and recombinant human albumin sealant gel applied to the transected pancreatic margin in DP may reduce POPF rates and was assessed. METHODS: A retrospective single centre cohort study of patient undergoing DP at an Australian high volume tertiary institution between January 2015 and January 2021. Rates of POPF in patients undergoing stapled pancreatic transection with PEG sealant were compared to other methods. RESULTS: A total of 54 cases were identified for analysis, with 16 undergoing stapled DP combined with staple line application of PEG (PEG group). Most patients in the control group had stapled DP 92% (35 of 38), with 47% (18 of 38) combined with a reinforcing buttress, with or without the use other glue types. Overall, 28 of 54 (52%) developed a POPF, with a significantly lower rate in the PEG group (3 of 16 vs. 25 of 38 in the Control group; p = 0.003). Clinically significant Grade B/C POPF was lower in the PEG group (0 of 16 vs. 9 of 28 in the Control group; p = 0.045), and patients in the PEG group had a shorter median (range) length of hospital stay (6 [4-14] days vs. 10 [6-41] days p = 0.04). CONCLUSION: Stapled DP with the application of PEG and recombinant human albumin sealant to the transection line appears to be associated with a lower rate of clinically significant POPF.


Assuntos
Pancreatectomia , Fístula Pancreática , Austrália , Estudos de Coortes , Humanos , Pancreatectomia/efeitos adversos , Fístula Pancreática/prevenção & controle , Polietilenoglicóis/uso terapêutico , Complicações Pós-Operatórias/epidemiologia , Complicações Pós-Operatórias/prevenção & controle , Estudos Retrospectivos , Fatores de Risco , Albumina Sérica Humana
18.
ACS Biomater Sci Eng ; 6(10): 5609-5619, 2020 10 12.
Artigo em Inglês | MEDLINE | ID: mdl-33178887

RESUMO

Current dental sealants with methacrylate based chemistry are prone to hydrolytic degradation. A conventional ethylene glycol dimethacrylate (EGDMA) was compared to a novel methacrylate monomer with a flipped external ester group (ethylene glycol ethyl methacrylate - EGEMA) that was designed to resist polymer degradation effects. Fourier transform infrared spectroscopy and water contact angle confirmed a comparable degree of initial conversion and surface wettability for EGDMA and EGEMA. EGDMA disks initially performed better compared to EGEMA as suggested by higher surface hardness and 1.5 times higher diametral tensile strength (DTS). After 15 weeks of hydrolytic and accelerated aging, EGDMA and EGEMA DTS was reduced by 88% and 44% respectively. This accelerated aging model resulted in 3.3 times higher water sorption for EDGMA than EGEMA disks. EGDMA had an increase in grain boundary defects and visible erosion sites with accelerated aging, while for EGEMA the changes were not significant.


Assuntos
Ésteres , Polímeros , Dureza , Teste de Materiais , Resistência à Tração
19.
Dent Mater J ; 37(6): 995-1002, 2018 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-30135336

RESUMO

Cross-polarization optical coherence tomography (CP-OCT) is a promising imaging modality to detect demineralization under the margins of composite restorations. The aim of this study was to assess how base materials applied under composite resin may affect CP-OCT image assessment. Base materials are commonly used for managing deep dentinal decay but once applied residual amounts of the base materials can be inadvertently left on the inner enamel walls. This study determined that base materials have significantly different scattering properties. The order grouping in the mean backscattered reflectivity (mR) of the base material was Dycal>caries phantom>Fuji IX, Vitrebond, Fuji II (p<0.05). The calcium hydroxide base (Dycal) had a higher mR than demineralized dentin and Vitrebond before and after the resin restoration was placed (p<0.05). While calcium hydroxide maybe a confounder in CPOCT imaging, several protective base materials are compatible with this type of imaging modality.


Assuntos
Resinas Compostas/química , Cárie Dentária/diagnóstico por imagem , Materiais Dentários/química , Tomografia de Coerência Óptica/métodos , Desmineralização do Dente/diagnóstico por imagem , Hidróxido de Cálcio , Cárie Dentária/etiologia , Esmalte Dentário/química , Cimentos de Ionômeros de Vidro , Técnicas In Vitro , Minerais , Imagens de Fantasmas , Espalhamento de Radiação
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